US20180115186A1 - Energy management system - Google Patents
Energy management system Download PDFInfo
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- US20180115186A1 US20180115186A1 US15/838,719 US201715838719A US2018115186A1 US 20180115186 A1 US20180115186 A1 US 20180115186A1 US 201715838719 A US201715838719 A US 201715838719A US 2018115186 A1 US2018115186 A1 US 2018115186A1
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- voltage
- converter
- detected
- bidirectional
- inverter
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
- H02J7/35—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering with light sensitive cells
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/10—Parallel operation of dc sources
- H02J1/102—Parallel operation of dc sources being switching converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/10—Parallel operation of dc sources
- H02J1/12—Parallel operation of dc generators with converters, e.g. with mercury-arc rectifier
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/28—Arrangements for balancing of the load in a network by storage of energy
- H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/381—Dispersed generators
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/22—The renewable source being solar energy
- H02J2300/24—The renewable source being solar energy of photovoltaic origin
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2310/00—The network for supplying or distributing electric power characterised by its spatial reach or by the load
- H02J2310/10—The network having a local or delimited stationary reach
- H02J2310/12—The local stationary network supplying a household or a building
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E70/00—Other energy conversion or management systems reducing GHG emissions
- Y02E70/30—Systems combining energy storage with energy generation of non-fossil origin
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P90/00—Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
- Y02P90/50—Energy storage in industry with an added climate change mitigation effect
Definitions
- the present disclosure relates to an energy management system that uses electric power generated in houses, factories, or the like.
- a power generator such as, for example, a solar power generation system in which electric power generated by a solar panel is used in a house or the like includes a DC voltage bus (hereinafter an “HVDC bus”).
- a photovoltaic (hereinafter “PV”) converter, an inverter, a bidirectional DC-DC converter, and the like are connected to the HVDC bus.
- the PV converter outputs electric power generated by a solar power generation apparatus to the HVDC bus with a predetermined voltage.
- the bidirectional DC-DC converter to which a secondary battery is connected converts a DC voltage transferred/received between the secondary battery and the HVDC bus to a predetermined constant voltage.
- the inverter transmits the electric power generated by the power generator or the electric power stored in the secondary battery to an electric power system, and supplies electric power from the electric power system to the HVDC bus.
- Patent Document 1 discloses a power supply system, in which a plurality of power supply units are connected to a DC voltage bus that is capable of performing cooperative control.
- the power supply system disclosed in Patent Document 1 in which a plurality of power supply units such as a solar power generation unit or the like are connected to the DC voltage bus, autonomously determines a transfer/reception amount of electric power transferred/received with the DC voltage bus on the basis of a voltage of the DC voltage bus.
- the above-described solar power generation system generally includes a detection circuit for detecting the voltage of the HVDC bus in order to maintain the voltage of the HVDC bus at a predetermined value and controls the voltage by switching control or the like such that the detection result becomes the predetermined voltage.
- Patent Document 1 Japanese Unexamined Patent Application Publication No. 2005-224009.
- the voltage of the DC voltage bus is desirably set so as to be maintained at a lower voltage value while being close to the desired voltage value as much as possible.
- an energy management system includes a DC voltage bus; a power generation apparatus connected to the DC voltage bus and that outputs generated electric power to the DC voltage bus; a bidirectional DC-DC converter connected to the DC voltage bus and to which a DC voltage is inputted from the DC voltage bus or outputting a DC voltage to the DC voltage bus; and an inverter connected to the DC voltage bus that converts a DC voltage inputted from the DC voltage bus to an AC voltage.
- each of the power generation apparatus, the bidirectional DC-DC converter, and the inverter has a voltage detection portion detecting a voltage of the DC voltage bus, and a switching control unit carrying out switching control such that the voltage that the voltage detection portion detects matches with a target value.
- the energy management system includes a calibration value setting unit that compares the voltages detected by the respective voltage detection portions and sets a calibration value to the highest voltage, and a calibration unit that calibrates the detection voltages of the voltage detection portions excluding the voltage detection portion which detects the highest voltage with the calibration value.
- each different detection result is calibrated so as to be the highest voltage among the detection results.
- each of the power generation apparatus, the bidirectional DC-DC converter, and the inverter carries out switching control using the voltage value after the calibration. This makes it possible to stabilize the voltage of the DC voltage bus, even if the voltage detection results by the plurality of voltage detection portions deviate with the lapse of time.
- the energy management system includes a controller area network, in which the power generation apparatus, the bidirectional DC-DC converter, and the inverter may be connected to the controller area network.
- intercommunication can be performed with serial bus communication which does not need master-slave setting and is resistant to noise.
- the energy management system can further include a setting unit that sets a timing when voltage fluctuations of the DC voltage bus are minimized during a predetermined period, in which the calibration unit calibrates at the timing set by the setting unit.
- the energy management system may include a temperature detection unit that detects an ambient temperature, and a correction unit that corrects the detection voltage by the voltage detection portion in accordance with the temperature detected by the temperature detection unit.
- the error in the detection result of the voltage which is caused by a difference in the temperature by a season, a time zone, or the like, can be further suppressed.
- the power generation apparatus, the bidirectional DC-DC converter, and the inverter may be configured to each have the temperature detection unit.
- an energy management system is capable of taking a countermeasure for stabilizing a voltage of a DC voltage bus at a predetermined value, and is capable of prolonging a lifespan of a component, even in a case where a voltage detection result deviates with a lapse of time.
- FIG. 1 is a diagram illustrating an energy management system according to an exemplary embodiment.
- FIG. 2 is a diagram illustrating the configuration of a PV converter included in a power generation apparatus.
- FIG. 3 is a diagram illustrating the configuration of a bidirectional DC-DC converter.
- FIG. 4 is a diagram illustrating the configuration of an inverter.
- FIG. 5 is a diagram for explaining detection bus voltage calibration control.
- FIG. 6 is a flowchart illustrating operations of the bidirectional DC-DC converter.
- FIG. 7 is a flowchart illustrating operations of the PV converter and the inverter.
- FIG. 1 is a diagram illustrating an energy management system 1 according to an exemplary embodiment.
- the energy management system 1 includes a power generation apparatus 20 (i.e., a “power generator”), a bidirectional DC-DC converter 30 , an inverter 40 , and a controller 50 .
- the power generation apparatus 20 , the bidirectional DC-DC converter 30 , and the inverter 40 are connected to an HVDC bus 10 .
- the HVDC bus 10 is an example of a “DC voltage bus” according to the present disclosure.
- each controller described herein can comprises a computer processor, a microprocessor, a microcontroller, or the like that includes memory with software stored thereon that, when executed by the processing unit, is configured to each the respective algorithms as described herein.
- the power generation apparatus 20 the bidirectional DC-DC converter 30 , and the inverter 40 are connected so as to be able to perform data communication with one another through a controller area network (CAN).
- CAN controller area network
- the power generation apparatus 20 includes an optical power generation panel 21 and a PV converter 22 .
- the PV converter 22 outputs electric power generated by the optical power generation panel 21 to the HVDC bus 10 .
- the power generation apparatus 20 may be a wind power generation apparatus, a gas power generation apparatus, or the like.
- the power generation apparatus 20 detects an output voltage and an output current. Furthermore, based on the detected output voltage and output current, maximum power point tracking (MPPT) control for maximizing output electric power is performed. A power generation amount by the optical power generation panel 21 fluctuates depending on an environment (an installation place, weather, or the like). Accordingly, the power generation apparatus 20 outputs the maximum electric power according to the environment at the time by performing MPPT control.
- MPPT maximum power point tracking
- a secondary battery B 1 is connected to the bidirectional DC-DC converter 30 .
- the bidirectional DC-DC converter 30 converts (steps up or steps down) the DC voltage outputted from the PV converter 22 to the HVDC bus 10 , and charges the secondary battery B 1 . Additionally, the bidirectional DC-DC converter 30 converts the DC voltage with which the secondary battery B 1 is charged, and outputs the resulting voltage to the HVDC bus 10 .
- the inverter 40 is connected to an electric power system 101 and a distribution board 102 with the switches S 1 and S 2 interposed therebetween.
- An AC output terminal (AC outlet or the like), which is not illustrated, is connected to the distribution board 102 .
- a load such as a microwave oven, a washing machine, an air conditioner, or the like is connected to the AC output terminal.
- the inverter 40 converts the DC voltage inputted from the HVDC bus 10 to an AC voltage, and outputs the resulting voltage to the electric power system 101 side. Additionally, the inverter 40 converts an AC voltage inputted from the electric power system 101 side to a DC voltage, and outputs the resulting voltage to the HVDC bus 10 .
- the switches S 1 and S 2 are turned on at a normal state in which there is no abnormality in the electric power system 101 (for example, a power outage). Additionally, the switches S 1 and S 2 are turned off in a case where the electric power system 101 is abnormal. Turning the switches S 1 and S 2 off makes it possible to prevent the voltage outputted from the inverter 40 from flowing into the electric power system 101 .
- the controller 50 controls the energy management system 1 as a whole. For example, the controller 50 performs on/off control of the switches S 1 and S 2 in accordance with presence or absence of the abnormality in the electric power system 101 .
- the controller 50 has a timing setting portion 51 .
- the timing setting portion 51 is an example of a “setting unit” according to the present disclosure.
- the timing setting portion 51 sets a timing when detection bus voltage calibration control is executed as will be described below. It is noted that in general each “portion” or component described herein includes appropriate electronic circuitry in order to perform the stated function of the component.
- the detection bus voltage calibration control is preferably performed when the voltage of the HVDC bus 10 stabilizes (when there is little voltage fluctuation). Accordingly, the timing setting portion 51 sets the timing under a condition such as a state where the voltage fluctuations of the HVDC bus 10 are within ⁇ 10 V, a state where there is almost no electric power transfer/reception in the PV converter 22 or the like, a standby state immediately after the end of solar power generation during daytime or immediately after the end of discharge of the secondary battery during nighttime, or the like, for example. Particularly, in a predetermined period (for example, one day, one week, one month, one year, or the like), a timing when the voltage fluctuations of the HVDC bus 10 are minimized is desirably set. It is noted that the timing may be set in advance in an exemplary aspect.
- FIG. 2 is a diagram illustrating the configuration of the PV converter 22 included in the power generation apparatus 20 .
- the PV converter 22 has a voltage detection portion 221 , a temperature compensation portion 222 , a voltage value output portion 223 , a voltage calibration portion 224 , a converter portion 225 , and a controller 226 .
- the voltage detection portion 221 can include a voltage detector that is configured to detect an output voltage of the PV converter 22 , that is, the voltage of the HVDC bus 10 .
- the PV converter 22 has voltage dividing resistances R 21 and R 22 connected to the HVDC bus 10 .
- the voltage detection portion 221 detects the voltage of the HVDC bus 10 with these voltage dividing resistances R 21 and R 22 .
- the temperature compensation portion 222 can include a temperature sensor that detects temperature of the PV converter 22 (inside and periphery), and can be configured to correct the voltage that the voltage detection portion 221 detects in accordance with the detected temperature.
- the temperature compensation portion 222 is an example of a “temperature detection unit” and a “correction unit” according to the present disclosure. Temperature in the energy management system 1 changes depending on a time zone or a season. Because of this temperature change, resistance values of the voltage dividing resistances R 21 and R 22 change. Accordingly, a voltage detection result by the voltage detection portion 221 includes an error caused by the temperature. Therefore, the temperature compensation portion 222 corrects the voltage that the voltage detection portion 221 detects on the basis of temperature characteristics. This makes it possible to further suppress the error in the detection result of the voltage by the voltage detection portion 221 .
- the temperature characteristics are calculated, for example, using a change in a temperature rise value and a sensitivity correction value obtained by performing sensitivity calibration of the energy management system 1 between with no load and during rated driving operation in the manufacturing period. Additionally, it is unlikely that the temperature characteristics largely change with the lapse of time, the temperature characteristics set once is desirably fixed.
- the voltage value output portion 223 outputs the voltage value detected by the voltage detection portion 221 to the bidirectional DC-DC converter 30 (e.g., by the connections shown as dashed arrows in FIG. 1 ). At this time, when the voltage value has been corrected by the temperature compensation portion 222 , the voltage value output portion 223 outputs the voltage value after the correction. It is noted that, as described above, since the power generation apparatus 20 and the bidirectional DC-DC converter 30 are connected through the CAN (i.e., the bi-directional dashed arrows), the voltage value outputted from the PV converter 22 to the bidirectional DC-DC converter 30 can be outputted without being affected by noise.
- the voltage calibration portion 224 calibrates the voltage detected by the voltage detection portion 221 .
- the voltage calibration portion 224 is an example of a “calibration unit” or “calibrator” according to the present disclosure.
- the bidirectional DC-DC converter 30 sets a calibration value of the voltage.
- the voltage calibration portion 224 acquires the calibration value from the bidirectional DC-DC converter 30 .
- the voltage calibration portion 224 calibrates the voltage detected by the voltage detection portion 221 to the calibration value.
- the voltage calibration portion 224 calibrates the voltage detected by the voltage detection portion 221 to 380 V (e.g., by increasing the detection voltage by 2 volts from 378 V to 380 V).
- the controller 226 carries out switching control on the converter portion 225 .
- the controller 226 is an example of a “switching control unit” according to the present disclosure.
- the voltage detected by the voltage detection portion 221 is fed back to the controller 226 .
- the controller 226 carries out switching control on the converter portion 225 such that the voltage that the voltage detection portion 221 detects approaches a target value.
- the voltage fed back to the controller 226 is the voltage which has been corrected by the temperature compensation portion 222 and calibrated by the voltage calibration portion 224 .
- FIG. 3 is a diagram illustrating the configuration of the bidirectional DC-DC converter 30 .
- the bidirectional DC-DC converter 30 has a voltage detection portion 31 , a temperature compensation portion 32 , a calibration value setting portion 33 , a voltage calibration portion 34 , a converter portion 35 , and a controller 36 .
- the voltage detection portion 31 can include a voltage detector that is configured to detect an output voltage to the HVDC bus 10 side of the bidirectional DC-DC converter 30 , that is, the voltage of the HVDC bus 10 .
- the bidirectional DC-DC converter 30 has voltage dividing resistances R 31 and R 32 connected to the HVDC bus 10 .
- the voltage detection portion 31 detects the voltage of the HVDC bus 10 with these voltage dividing resistances R 31 and R 32 .
- the temperature compensation portion 32 can include a temperature sensor configured to detect temperature of the bidirectional DC-DC converter 30 , and can correct the voltage that the voltage detection portion 31 detects in accordance with the detected temperature, in the same manner as the temperature compensation portion 222 of the PV converter 22 .
- the temperature compensation portion 32 is an example of a “temperature detection unit” and a “correction unit” according to the present disclosure.
- the calibration value setting portion 33 (e.g., a calibration value selector) can include a comparator (or similar circuitry) that is configured to compare the voltages detected by the power generation apparatus 20 and the inverter 40 and the voltage detected by the voltage detection portion 31 , and to set a calibration value to the highest voltage value.
- the calibration value setting portion 33 outputs the set calibration value to the power generation apparatus 20 and the inverter 40 .
- the calibration value setting portion 33 sets the calibration value to the highest voltage value among voltages each detected by the power generation apparatus 20 , the inverter 40 , and the bidirectional DC-DC converter 30 . Then, such that the voltages each detected by the voltage detection portion 221 and a voltage detection portion 41 can be calibrated to the calibration value described above, the calibration value is transmitted to the power generation apparatus 20 and the inverter 40 .
- the calibration value setting portion 33 is an example of a “calibration value setting unit” according to the present disclosure.
- the voltage calibration portion 34 calibrates the voltage detected by the voltage detection portion 31 to the calibration value set by the calibration value setting portion 33 .
- the voltage calibration portion 34 is an example of a “calibration unit” or “calibrator” according to the present disclosure.
- the controller 36 carries out switching control on the converter portion 35 .
- the controller 36 is an example of a “switching control unit” according to the present disclosure.
- the voltage detected by the voltage detection portion 31 is fed back to the controller 36 .
- the controller 36 carries out switching control on the converter portion 35 such that the voltage that the voltage detection portion 31 detects approaches the target value.
- the voltage fed back to the controller 36 is the voltage which has been corrected by the temperature compensation portion 32 and calibrated by the voltage calibration portion 34 .
- FIG. 4 is a diagram illustrating the configuration of the inverter 40 .
- the inverter 40 has the voltage detection portion 41 , a temperature compensation portion 42 , a voltage value output portion 43 , a voltage calibration portion 44 , an inverter portion 45 , and a controller 46 .
- the voltage detection portion 41 includes a voltage detector that is configured to detect an output voltage of the inverter 40 , that is, the voltage of the HVDC bus 10 .
- the inverter 40 has voltage dividing resistances R 41 and R 42 connected to the HVDC bus 10 .
- the voltage detection portion 41 detects the voltage of the HVDC bus 10 with these voltage dividing resistances R 41 and R 42 .
- the temperature compensation portion 42 can include a temperature sensor configured to detect the temperature of the inverter 40 (inside and periphery), and is configure to correct the voltage that the voltage detection portion 41 detects in accordance with the detected temperature, in the same manner as the temperature compensation portion 222 of the PV converter 22 as described above.
- the temperature compensation portion 42 is an example of a “temperature detection unit” and a “correction unit” according to the present disclosure.
- the voltage value output portion 43 outputs the voltage value detected by the voltage detection portion 41 to the bidirectional DC-DC converter 30 . At this time, when the voltage value has been corrected with respect to the temperature by the temperature compensation portion 42 , the voltage value output portion 43 outputs the voltage value after the correction.
- the voltage calibration portion 44 calibrates the voltage detected by the voltage detection portion 41 to the calibration value set by the calibration value setting portion 33 of the bidirectional DC-DC converter 30 .
- the controller 46 carries out switching control on the inverter portion 45 .
- the controller 46 is an example of a “switching control unit” according to the present disclosure.
- the voltage detected by the voltage detection portion 41 is fed back to the controller 46 .
- the controller 46 carries out switching control on the inverter portion 45 such that the voltage that the voltage detection portion 41 detects approaches the target value.
- the voltage fed back to the controller 46 is the voltage which has been corrected by the temperature compensation portion 42 and calibrated by the voltage calibration portion 44 .
- FIG. 5 is a diagram for explaining the detection bus voltage calibration control.
- the voltages of the HVDC bus 10 each detected by the PV converter 22 , the bidirectional DC-DC converter 30 , and the inverter 40 ideally match with one another.
- detection accuracy of the energy management system 1 drops due to long-term use thereof or the like and variation in detection results occurs as illustrated in FIG. 5 in some cases.
- the detection bus voltage calibration control the detected voltage values are compared, and a calibration value is set to the highest detected voltage value.
- the setting of the calibration value is performed by the calibration value setting portion 33 included in the bidirectional DC-DC converter 30 as described above.
- the calibration value setting portion 33 sets the calibration value to the highest voltage 385 V detected by the inverter 40 .
- the calibration value setting portion 33 outputs the set calibration value to the PV converter 22 and the inverter 40 .
- the PV converter 22 , the bidirectional DC-DC converter 30 , and the inverter 40 each calibrate the detected voltages of the HVDC bus 10 to the calibration value (385 V). Then, the PV converter 22 , the bidirectional DC-DC converter 30 , and the inverter 40 each carry out switching control such that the output voltages approach the target value using the voltage after the calibration.
- the detected voltage which is 378 V
- the PV converter 22 carries out switching control on the basis of the voltage value after the calibration, such that the voltage of the target value is outputted.
- the bidirectional DC-DC converter 30 the detected voltage, which is 380 V, is calibrated to the calibration value 385 V. Then, the bidirectional DC-DC converter 30 carries out switching control on the basis of the voltage value after the calibration, such that the voltage of the target value is outputted.
- the voltages of the HVDC bus 10 are adjusted to a constant value. Additionally, by setting the calibration value of the voltage to the highest voltage among the detection voltages, the voltage of the HVDC bus 10 after the calibration has a tendency to be lower than that before the calibration.
- the voltage of the HVDC bus 10 is 380 V
- the voltage of the HVDC bus 10 is controlled to be approximately 375 V ( ⁇ 380 ⁇ 380/385).
- the calibration value setting portion 33 sets the calibration value to 380 V.
- the calibration value setting portion 33 sets the calibration value to 387 V. In this case, the voltage of the HVDC bus 10 is controlled to be approximately 373 V ( ⁇ 380 ⁇ 380/387).
- this detection bus voltage calibration control is designed so as to adjust the detection voltages to the lowest voltage value thereamong, the voltage of the HVDC bus 10 after the calibration inclines to be controlled toward a higher voltage.
- the high voltage is applied to each component of the PV converter 22 or the like.
- a lifespan or the like of each component is reduced.
- setting the calibration value to the highest voltage value among the detection voltages and controlling the voltage of the HVDC bus 10 by the value after the calibration make it possible to tendency to lower the voltage applied to each component of the PV converter 22 or the like. Accordingly, reliability of each component can be improved.
- FIG. 6 is a flowchart illustrating operations of the bidirectional DC-DC converter 30 .
- the bidirectional DC-DC converter 30 determines whether or not to perform a calibration timing (S 11 ).
- the calibration timing is an execution timing of the detection bus voltage calibration control set by the timing setting portion 51 of the controller 50 .
- the bidirectional DC-DC converter 30 is to not perform the calibration timing (S 11 : NO), the present processing ends.
- the voltage detection portion 31 detects a voltage (S 12 ).
- the temperature compensation portion 32 detects temperature (S 13 ), and corrects the voltage detected by the voltage detection portion 31 using temperature characteristics (S 14 ).
- the calibration value setting portion 33 acquires the voltage detected by the voltage detection portion 31 , and the voltages detected by the PV converter 22 and the inverter 40 (S 15 ). Subsequently, the calibration value setting portion 33 sets a calibration value to the highest voltage value among these voltages (S 16 ). The voltage calibration portion 34 calibrates the voltage detected by the voltage detection portion 31 in S 12 to the set calibration value (S 17 ). Thereafter, the controller 36 carries out switching control on the converter portion 35 using the voltage after the calibration such that the voltage of the target value is outputted.
- FIG. 7 is a flowchart illustrating operations of the PV converter 22 and the inverter 40 .
- the PV converter 22 and the inverter 40 have the same operations, and therefore the operations of the PV converter 22 will be described below.
- the PV converter 22 first determines whether or not to perform the calibration timing set by the timing setting portion 51 of the controller 50 (S 21 ). When the calibration timing is not to be performed (S 21 : NO), the present processing ends. However, when the calibration timing is to be performed (S 21 : YES), the voltage detection portion 221 of the PV converter 22 detects a voltage (S 22 ). Next, the temperature compensation portion 222 detects temperature (S 23 ), and corrects the voltage detected by the voltage detection portion 221 based on the temperature characteristics (S 24 ).
- the voltage value output portion 223 outputs the voltage detected by the voltage detection portion 221 to the bidirectional DC-DC converter 30 (S 25 ). Subsequently, the voltage calibration portion 224 determines whether or not the calibration value set by the bidirectional DC-DC converter 30 is received (S 26 ). When it is not received (S 26 : NO), the voltage calibration portion 224 stands by until the reception of the calibration value.
- the voltage calibration portion 224 calibrates the voltage detected by the voltage detection portion 221 in S 22 to the set calibration value (S 27 ). Thereafter, the controller 226 carries out switching control on the converter portion 225 using the voltage after the calibration such that the voltage of the target value is outputted.
- the calibration value may be set by any of the PV converter 22 , the inverter 40 , and the controller 50 .
- the power generation apparatus 20 the bidirectional DC-DC converter 30 , and the inverter 40 each detect the temperature in order to detect more accurate temperature
- one member of the energy management system 1 may detect the temperature, and the power generation apparatus 20 or the like may perform a voltage correction using the detection result.
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Abstract
Description
- The present application is a continuation of PCT/JP2016/067161 filed Jun. 9, 2016, which claims priority to Japanese Patent Application No. 2015-126178, filed June 24, 2015, the entire contents of each of which are incorporated herein by reference.
- The present disclosure relates to an energy management system that uses electric power generated in houses, factories, or the like.
- A power generator such as, for example, a solar power generation system in which electric power generated by a solar panel is used in a house or the like includes a DC voltage bus (hereinafter an “HVDC bus”). A photovoltaic (hereinafter “PV”) converter, an inverter, a bidirectional DC-DC converter, and the like are connected to the HVDC bus. The PV converter outputs electric power generated by a solar power generation apparatus to the HVDC bus with a predetermined voltage. The bidirectional DC-DC converter to which a secondary battery is connected converts a DC voltage transferred/received between the secondary battery and the HVDC bus to a predetermined constant voltage. Furthermore, the inverter transmits the electric power generated by the power generator or the electric power stored in the secondary battery to an electric power system, and supplies electric power from the electric power system to the HVDC bus.
- Patent Document 1 (identified below), for example, discloses a power supply system, in which a plurality of power supply units are connected to a DC voltage bus that is capable of performing cooperative control. The power supply system disclosed in
Patent Document 1, in which a plurality of power supply units such as a solar power generation unit or the like are connected to the DC voltage bus, autonomously determines a transfer/reception amount of electric power transferred/received with the DC voltage bus on the basis of a voltage of the DC voltage bus. It is noted that the above-described solar power generation system generally includes a detection circuit for detecting the voltage of the HVDC bus in order to maintain the voltage of the HVDC bus at a predetermined value and controls the voltage by switching control or the like such that the detection result becomes the predetermined voltage. - Patent Document 1: Japanese Unexamined Patent Application Publication No. 2005-224009.
- In general, it is expected that the solar power generation system or the like will be used for a long period. However, an error (deviation) may occur in the detection result of the voltage by the detection circuit described above during the long-term use. For example, in
Patent Document 1, the detection voltage of each of the power supply units varies with respect to a true value of the voltage of the HVDC bus. As a result, there is a risk that the voltage of the DC voltage bus does not stabilize. - In other words, because the values of the detection voltages detected by the respective power supply units are different, it is difficult to stably control the HVDC bus voltage. Accordingly, countermeasures against the error in the detection circuit caused by the long-term use are needed. Additionally, when a higher voltage than a desired voltage value (for example 380 V) is continuously applied to each component such as a PV converter or the like connected to the HVDC bus, there is a problem that a lifespan thereof shortens. Accordingly, the voltage of the DC voltage bus is desirably set so as to be maintained at a lower voltage value while being close to the desired voltage value as much as possible.
- Thus, it is an object of the present disclosure to provide an energy management system capable of taking a countermeasure for stabilizing a voltage of a DC voltage bus and capable of prolonging a lifespan of a component, even in a case where a voltage detection result deviates at a plurality of voltage detection portions with a lapse of time.
- Accordingly, an energy management system is disclosed that includes a DC voltage bus; a power generation apparatus connected to the DC voltage bus and that outputs generated electric power to the DC voltage bus; a bidirectional DC-DC converter connected to the DC voltage bus and to which a DC voltage is inputted from the DC voltage bus or outputting a DC voltage to the DC voltage bus; and an inverter connected to the DC voltage bus that converts a DC voltage inputted from the DC voltage bus to an AC voltage. Moreover, each of the power generation apparatus, the bidirectional DC-DC converter, and the inverter has a voltage detection portion detecting a voltage of the DC voltage bus, and a switching control unit carrying out switching control such that the voltage that the voltage detection portion detects matches with a target value. Furthermore, the energy management system includes a calibration value setting unit that compares the voltages detected by the respective voltage detection portions and sets a calibration value to the highest voltage, and a calibration unit that calibrates the detection voltages of the voltage detection portions excluding the voltage detection portion which detects the highest voltage with the calibration value.
- The voltage detection results by the power generation apparatus, the bidirectional DC-DC converter, and the inverter do not match with one another due to errors occurring with the lapse of time. Accordingly, in this configuration, each different detection result is calibrated so as to be the highest voltage among the detection results. Additionally, each of the power generation apparatus, the bidirectional DC-DC converter, and the inverter carries out switching control using the voltage value after the calibration. This makes it possible to stabilize the voltage of the DC voltage bus, even if the voltage detection results by the plurality of voltage detection portions deviate with the lapse of time.
- Additionally, setting the calibration value to the highest voltage value among the detection voltages and controlling the voltage of the DC voltage bus with the value after the calibration makes it possible to lower the voltage applied to each component of each of the power generation apparatus, the bidirectional DC-DC converter, and the inverter. As a result, the lifespans of the components can be prolonged.
- The energy management system according to the present disclosure includes a controller area network, in which the power generation apparatus, the bidirectional DC-DC converter, and the inverter may be connected to the controller area network.
- According to this configuration, intercommunication can be performed with serial bus communication which does not need master-slave setting and is resistant to noise.
- The energy management system according to the present disclosure can further include a setting unit that sets a timing when voltage fluctuations of the DC voltage bus are minimized during a predetermined period, in which the calibration unit calibrates at the timing set by the setting unit.
- According to this configuration, accurate calibrations can be performed by calibrating the voltage when the voltage of the DC voltage bus experiences little fluctuations.
- The energy management system according to the present disclosure may include a temperature detection unit that detects an ambient temperature, and a correction unit that corrects the detection voltage by the voltage detection portion in accordance with the temperature detected by the temperature detection unit.
- According to this configuration, the error in the detection result of the voltage, which is caused by a difference in the temperature by a season, a time zone, or the like, can be further suppressed.
- The power generation apparatus, the bidirectional DC-DC converter, and the inverter may be configured to each have the temperature detection unit.
- According to this configuration, it is possible to further accurately detect the temperature, and as a result, the error in the detection result of the voltage caused by the difference in the temperature can be further suppressed.
- According to the present disclosure, an energy management system can be provided that is capable of taking a countermeasure for stabilizing a voltage of a DC voltage bus at a predetermined value, and is capable of prolonging a lifespan of a component, even in a case where a voltage detection result deviates with a lapse of time.
-
FIG. 1 is a diagram illustrating an energy management system according to an exemplary embodiment. -
FIG. 2 is a diagram illustrating the configuration of a PV converter included in a power generation apparatus. -
FIG. 3 is a diagram illustrating the configuration of a bidirectional DC-DC converter. -
FIG. 4 is a diagram illustrating the configuration of an inverter. -
FIG. 5 is a diagram for explaining detection bus voltage calibration control. -
FIG. 6 is a flowchart illustrating operations of the bidirectional DC-DC converter. -
FIG. 7 is a flowchart illustrating operations of the PV converter and the inverter. -
FIG. 1 is a diagram illustrating anenergy management system 1 according to an exemplary embodiment. - The
energy management system 1 includes a power generation apparatus 20 (i.e., a “power generator”), a bidirectional DC-DC converter 30, aninverter 40, and acontroller 50. Thepower generation apparatus 20, the bidirectional DC-DC converter 30, and theinverter 40 are connected to anHVDC bus 10. The HVDCbus 10 is an example of a “DC voltage bus” according to the present disclosure. It is noted that each controller described herein can comprises a computer processor, a microprocessor, a microcontroller, or the like that includes memory with software stored thereon that, when executed by the processing unit, is configured to each the respective algorithms as described herein. - Additionally, the
power generation apparatus 20, the bidirectional DC-DC converter 30, and theinverter 40 are connected so as to be able to perform data communication with one another through a controller area network (CAN). By connecting the apparatuses through the CAN, intercommunication can be performed between the apparatuses with serial bus communication without requiring master-slave setting while being resistant to noise. - The
power generation apparatus 20 includes an opticalpower generation panel 21 and aPV converter 22. ThePV converter 22 outputs electric power generated by the opticalpower generation panel 21 to theHVDC bus 10. it is noted that thepower generation apparatus 20 may be a wind power generation apparatus, a gas power generation apparatus, or the like. - The
power generation apparatus 20 detects an output voltage and an output current. Furthermore, based on the detected output voltage and output current, maximum power point tracking (MPPT) control for maximizing output electric power is performed. A power generation amount by the opticalpower generation panel 21 fluctuates depending on an environment (an installation place, weather, or the like). Accordingly, thepower generation apparatus 20 outputs the maximum electric power according to the environment at the time by performing MPPT control. - A secondary battery B1 is connected to the bidirectional DC-
DC converter 30. The bidirectional DC-DC converter 30 converts (steps up or steps down) the DC voltage outputted from thePV converter 22 to theHVDC bus 10, and charges the secondary battery B1. Additionally, the bidirectional DC-DC converter 30 converts the DC voltage with which the secondary battery B1 is charged, and outputs the resulting voltage to theHVDC bus 10. - The
inverter 40 is connected to anelectric power system 101 and adistribution board 102 with the switches S1 and S2 interposed therebetween. An AC output terminal (AC outlet or the like), which is not illustrated, is connected to thedistribution board 102. A load such as a microwave oven, a washing machine, an air conditioner, or the like is connected to the AC output terminal. Theinverter 40 converts the DC voltage inputted from theHVDC bus 10 to an AC voltage, and outputs the resulting voltage to theelectric power system 101 side. Additionally, theinverter 40 converts an AC voltage inputted from theelectric power system 101 side to a DC voltage, and outputs the resulting voltage to theHVDC bus 10. - The switches S1 and S2 are turned on at a normal state in which there is no abnormality in the electric power system 101 (for example, a power outage). Additionally, the switches S1 and S2 are turned off in a case where the
electric power system 101 is abnormal. Turning the switches S1 and S2 off makes it possible to prevent the voltage outputted from theinverter 40 from flowing into theelectric power system 101. - The controller 50 (e.g., a computer processing unit) controls the
energy management system 1 as a whole. For example, thecontroller 50 performs on/off control of the switches S1 and S2 in accordance with presence or absence of the abnormality in theelectric power system 101. - The
controller 50 has atiming setting portion 51. Thetiming setting portion 51 is an example of a “setting unit” according to the present disclosure. Thetiming setting portion 51 sets a timing when detection bus voltage calibration control is executed as will be described below. It is noted that in general each “portion” or component described herein includes appropriate electronic circuitry in order to perform the stated function of the component. - The detection bus voltage calibration control is preferably performed when the voltage of the
HVDC bus 10 stabilizes (when there is little voltage fluctuation). Accordingly, thetiming setting portion 51 sets the timing under a condition such as a state where the voltage fluctuations of theHVDC bus 10 are within ±10 V, a state where there is almost no electric power transfer/reception in thePV converter 22 or the like, a standby state immediately after the end of solar power generation during daytime or immediately after the end of discharge of the secondary battery during nighttime, or the like, for example. Particularly, in a predetermined period (for example, one day, one week, one month, one year, or the like), a timing when the voltage fluctuations of theHVDC bus 10 are minimized is desirably set. It is noted that the timing may be set in advance in an exemplary aspect. - Hereinafter, the configuration of each of the
power generation apparatus 20, the bidirectional DC-DC converter 30, and theinverter 40 will be described in detail. -
FIG. 2 is a diagram illustrating the configuration of thePV converter 22 included in thepower generation apparatus 20. - The
PV converter 22 has avoltage detection portion 221, atemperature compensation portion 222, a voltagevalue output portion 223, avoltage calibration portion 224, aconverter portion 225, and acontroller 226. - The
voltage detection portion 221 can include a voltage detector that is configured to detect an output voltage of thePV converter 22, that is, the voltage of theHVDC bus 10. In an exemplary aspect, thePV converter 22 has voltage dividing resistances R21 and R22 connected to theHVDC bus 10. Thevoltage detection portion 221 detects the voltage of theHVDC bus 10 with these voltage dividing resistances R21 and R22. - The
temperature compensation portion 222 can include a temperature sensor that detects temperature of the PV converter 22 (inside and periphery), and can be configured to correct the voltage that thevoltage detection portion 221 detects in accordance with the detected temperature. Thetemperature compensation portion 222 is an example of a “temperature detection unit” and a “correction unit” according to the present disclosure. Temperature in theenergy management system 1 changes depending on a time zone or a season. Because of this temperature change, resistance values of the voltage dividing resistances R21 and R22 change. Accordingly, a voltage detection result by thevoltage detection portion 221 includes an error caused by the temperature. Therefore, thetemperature compensation portion 222 corrects the voltage that thevoltage detection portion 221 detects on the basis of temperature characteristics. This makes it possible to further suppress the error in the detection result of the voltage by thevoltage detection portion 221. - It is noted that the temperature characteristics are calculated, for example, using a change in a temperature rise value and a sensitivity correction value obtained by performing sensitivity calibration of the
energy management system 1 between with no load and during rated driving operation in the manufacturing period. Additionally, it is unlikely that the temperature characteristics largely change with the lapse of time, the temperature characteristics set once is desirably fixed. - The voltage
value output portion 223 outputs the voltage value detected by thevoltage detection portion 221 to the bidirectional DC-DC converter 30 (e.g., by the connections shown as dashed arrows inFIG. 1 ). At this time, when the voltage value has been corrected by thetemperature compensation portion 222, the voltagevalue output portion 223 outputs the voltage value after the correction. It is noted that, as described above, since thepower generation apparatus 20 and the bidirectional DC-DC converter 30 are connected through the CAN (i.e., the bi-directional dashed arrows), the voltage value outputted from thePV converter 22 to the bidirectional DC-DC converter 30 can be outputted without being affected by noise. - The
voltage calibration portion 224 calibrates the voltage detected by thevoltage detection portion 221. Thevoltage calibration portion 224 is an example of a “calibration unit” or “calibrator” according to the present disclosure. As will be described later in detail, the bidirectional DC-DC converter 30 sets a calibration value of the voltage. Thevoltage calibration portion 224 acquires the calibration value from the bidirectional DC-DC converter 30. Then, thevoltage calibration portion 224 calibrates the voltage detected by thevoltage detection portion 221 to the calibration value. For example, when the voltage detected by thevoltage detection portion 221 is 378 V and the calibration value set by the bidirectional DC-DC converter 30 is 380 V, thevoltage calibration portion 224 calibrates the voltage detected by thevoltage detection portion 221 to 380 V (e.g., by increasing the detection voltage by 2 volts from 378 V to 380 V). - The
controller 226 carries out switching control on theconverter portion 225. Thecontroller 226 is an example of a “switching control unit” according to the present disclosure. The voltage detected by thevoltage detection portion 221 is fed back to thecontroller 226. Then, thecontroller 226 carries out switching control on theconverter portion 225 such that the voltage that thevoltage detection portion 221 detects approaches a target value. At this time, the voltage fed back to thecontroller 226 is the voltage which has been corrected by thetemperature compensation portion 222 and calibrated by thevoltage calibration portion 224. -
FIG. 3 is a diagram illustrating the configuration of the bidirectional DC-DC converter 30. - The bidirectional DC-
DC converter 30 has avoltage detection portion 31, atemperature compensation portion 32, a calibrationvalue setting portion 33, avoltage calibration portion 34, aconverter portion 35, and acontroller 36. - The
voltage detection portion 31 can include a voltage detector that is configured to detect an output voltage to theHVDC bus 10 side of the bidirectional DC-DC converter 30, that is, the voltage of theHVDC bus 10. The bidirectional DC-DC converter 30 has voltage dividing resistances R31 and R32 connected to theHVDC bus 10. Thevoltage detection portion 31 detects the voltage of theHVDC bus 10 with these voltage dividing resistances R31 and R32. - The
temperature compensation portion 32 can include a temperature sensor configured to detect temperature of the bidirectional DC-DC converter 30, and can correct the voltage that thevoltage detection portion 31 detects in accordance with the detected temperature, in the same manner as thetemperature compensation portion 222 of thePV converter 22. Thetemperature compensation portion 32 is an example of a “temperature detection unit” and a “correction unit” according to the present disclosure. - The calibration value setting portion 33 (e.g., a calibration value selector) can include a comparator (or similar circuitry) that is configured to compare the voltages detected by the
power generation apparatus 20 and theinverter 40 and the voltage detected by thevoltage detection portion 31, and to set a calibration value to the highest voltage value. The calibrationvalue setting portion 33 outputs the set calibration value to thepower generation apparatus 20 and theinverter 40. - In other words, the calibration
value setting portion 33 sets the calibration value to the highest voltage value among voltages each detected by thepower generation apparatus 20, theinverter 40, and the bidirectional DC-DC converter 30. Then, such that the voltages each detected by thevoltage detection portion 221 and avoltage detection portion 41 can be calibrated to the calibration value described above, the calibration value is transmitted to thepower generation apparatus 20 and theinverter 40. The calibrationvalue setting portion 33 is an example of a “calibration value setting unit” according to the present disclosure. - The
voltage calibration portion 34 calibrates the voltage detected by thevoltage detection portion 31 to the calibration value set by the calibrationvalue setting portion 33. Thevoltage calibration portion 34 is an example of a “calibration unit” or “calibrator” according to the present disclosure. - The
controller 36 carries out switching control on theconverter portion 35. Thecontroller 36 is an example of a “switching control unit” according to the present disclosure. The voltage detected by thevoltage detection portion 31 is fed back to thecontroller 36. Then, thecontroller 36 carries out switching control on theconverter portion 35 such that the voltage that thevoltage detection portion 31 detects approaches the target value. At this time, the voltage fed back to thecontroller 36 is the voltage which has been corrected by thetemperature compensation portion 32 and calibrated by thevoltage calibration portion 34. -
FIG. 4 is a diagram illustrating the configuration of theinverter 40. - The
inverter 40 has thevoltage detection portion 41, atemperature compensation portion 42, a voltagevalue output portion 43, avoltage calibration portion 44, aninverter portion 45, and acontroller 46. - The
voltage detection portion 41 includes a voltage detector that is configured to detect an output voltage of theinverter 40, that is, the voltage of theHVDC bus 10. Theinverter 40 has voltage dividing resistances R41 and R42 connected to theHVDC bus 10. Thevoltage detection portion 41 detects the voltage of theHVDC bus 10 with these voltage dividing resistances R41 and R42. - The
temperature compensation portion 42 can include a temperature sensor configured to detect the temperature of the inverter 40 (inside and periphery), and is configure to correct the voltage that thevoltage detection portion 41 detects in accordance with the detected temperature, in the same manner as thetemperature compensation portion 222 of thePV converter 22 as described above. Thetemperature compensation portion 42 is an example of a “temperature detection unit” and a “correction unit” according to the present disclosure. - The voltage
value output portion 43 outputs the voltage value detected by thevoltage detection portion 41 to the bidirectional DC-DC converter 30. At this time, when the voltage value has been corrected with respect to the temperature by thetemperature compensation portion 42, the voltagevalue output portion 43 outputs the voltage value after the correction. - The
voltage calibration portion 44 calibrates the voltage detected by thevoltage detection portion 41 to the calibration value set by the calibrationvalue setting portion 33 of the bidirectional DC-DC converter 30. - The
controller 46 carries out switching control on theinverter portion 45. Thecontroller 46 is an example of a “switching control unit” according to the present disclosure. The voltage detected by thevoltage detection portion 41 is fed back to thecontroller 46. Then, thecontroller 46 carries out switching control on theinverter portion 45 such that the voltage that thevoltage detection portion 41 detects approaches the target value. At this time, the voltage fed back to thecontroller 46 is the voltage which has been corrected by thetemperature compensation portion 42 and calibrated by thevoltage calibration portion 44. - Next, the detection bus voltage calibration control executed by the
energy management system 1 configured as described above will be described. -
FIG. 5 is a diagram for explaining the detection bus voltage calibration control. - Normally, the voltages of the
HVDC bus 10 each detected by thePV converter 22, the bidirectional DC-DC converter 30, and theinverter 40 ideally match with one another. However, detection accuracy of theenergy management system 1 drops due to long-term use thereof or the like and variation in detection results occurs as illustrated inFIG. 5 in some cases. Accordingly, in the detection bus voltage calibration control, the detected voltage values are compared, and a calibration value is set to the highest detected voltage value. The setting of the calibration value is performed by the calibrationvalue setting portion 33 included in the bidirectional DC-DC converter 30 as described above. - For example, in a “
case 1” illustrated inFIG. 5 , the voltage detected by thePV converter 22 is 378 V, the voltage detected by the bidirectional DC-DC converter 30 is 380 V, and the voltage detected by theinverter 40 is 385 V. In this case, the calibrationvalue setting portion 33 sets the calibration value to the highest voltage 385 V detected by theinverter 40. The calibrationvalue setting portion 33 outputs the set calibration value to thePV converter 22 and theinverter 40. - The
PV converter 22, the bidirectional DC-DC converter 30, and theinverter 40 each calibrate the detected voltages of theHVDC bus 10 to the calibration value (385 V). Then, thePV converter 22, the bidirectional DC-DC converter 30, and theinverter 40 each carry out switching control such that the output voltages approach the target value using the voltage after the calibration. - For example, in the
PV converter 22, the detected voltage, which is 378 V, is calibrated to thecalibration value 385 V. Then, thePV converter 22 carries out switching control on the basis of the voltage value after the calibration, such that the voltage of the target value is outputted. In the bidirectional DC-DC converter 30, the detected voltage, which is 380 V, is calibrated to thecalibration value 385 V. Then, the bidirectional DC-DC converter 30 carries out switching control on the basis of the voltage value after the calibration, such that the voltage of the target value is outputted. - As described above, by adjusting the voltages each detected by the
PV converter 22, the bidirectional DC-DC converter 30 and theinverter 40 to the calibration value, the voltages of theHVDC bus 10 are adjusted to a constant value. Additionally, by setting the calibration value of the voltage to the highest voltage among the detection voltages, the voltage of theHVDC bus 10 after the calibration has a tendency to be lower than that before the calibration. - In a case where the control is performed such that the voltage of the
HVDC bus 10 is 380 V, by calibrating the voltages of theHVDC bus 10 each detected by thePV converter 22, the bidirectional DC-DC converter 30 and theinverter 40 to 385 V, the voltage of theHVDC bus 10 is controlled to be approximately 375 V (≈380×380/385). - It is noted that in a “
case 2” illustrated inFIG. 5 , the calibrationvalue setting portion 33 sets the calibration value to 380 V. In this case, the voltage of theHVDC bus 10 is controlled to be 380 V (=380×380/380). Additionally, in a “case 3”, the calibrationvalue setting portion 33 sets the calibration value to 387 V. In this case, the voltage of theHVDC bus 10 is controlled to be approximately 373 V (≈380×380/387). - In a case where this detection bus voltage calibration control is designed so as to adjust the detection voltages to the lowest voltage value thereamong, the voltage of the
HVDC bus 10 after the calibration inclines to be controlled toward a higher voltage. In this case, the high voltage is applied to each component of thePV converter 22 or the like. By the high voltage being applied for a long period of time, a lifespan or the like of each component is reduced. However, as in the present embodiment, setting the calibration value to the highest voltage value among the detection voltages and controlling the voltage of theHVDC bus 10 by the value after the calibration make it possible to tendency to lower the voltage applied to each component of thePV converter 22 or the like. Accordingly, reliability of each component can be improved. - Hereinafter, operations executed by each of the
PV converter 22, the bidirectional DC-DC converter 30, and theinverter 40 will be described. -
FIG. 6 is a flowchart illustrating operations of the bidirectional DC-DC converter 30. - The bidirectional DC-
DC converter 30 determines whether or not to perform a calibration timing (S11). The calibration timing is an execution timing of the detection bus voltage calibration control set by thetiming setting portion 51 of thecontroller 50. When the bidirectional DC-DC converter 30 is to not perform the calibration timing (S11: NO), the present processing ends. - Alternatively, if the bidirectional DC-
DC converter 30 is to perform the calibration timing (S11: YES), thevoltage detection portion 31 detects a voltage (S12). Next, thetemperature compensation portion 32 detects temperature (S13), and corrects the voltage detected by thevoltage detection portion 31 using temperature characteristics (S14). - The calibration
value setting portion 33 acquires the voltage detected by thevoltage detection portion 31, and the voltages detected by thePV converter 22 and the inverter 40 (S15). Subsequently, the calibrationvalue setting portion 33 sets a calibration value to the highest voltage value among these voltages (S16). Thevoltage calibration portion 34 calibrates the voltage detected by thevoltage detection portion 31 in S12 to the set calibration value (S17). Thereafter, thecontroller 36 carries out switching control on theconverter portion 35 using the voltage after the calibration such that the voltage of the target value is outputted. -
FIG. 7 is a flowchart illustrating operations of thePV converter 22 and theinverter 40. ThePV converter 22 and theinverter 40 have the same operations, and therefore the operations of thePV converter 22 will be described below. - The
PV converter 22 first determines whether or not to perform the calibration timing set by thetiming setting portion 51 of the controller 50 (S21). When the calibration timing is not to be performed (S21: NO), the present processing ends. However, when the calibration timing is to be performed (S21: YES), thevoltage detection portion 221 of thePV converter 22 detects a voltage (S22). Next, thetemperature compensation portion 222 detects temperature (S23), and corrects the voltage detected by thevoltage detection portion 221 based on the temperature characteristics (S24). - The voltage
value output portion 223 outputs the voltage detected by thevoltage detection portion 221 to the bidirectional DC-DC converter 30 (S25). Subsequently, thevoltage calibration portion 224 determines whether or not the calibration value set by the bidirectional DC-DC converter 30 is received (S26). When it is not received (S26: NO), thevoltage calibration portion 224 stands by until the reception of the calibration value. - When the calibration value is received from the bidirectional DC-DC converter 30 (S26: YES), the
voltage calibration portion 224 calibrates the voltage detected by thevoltage detection portion 221 in S22 to the set calibration value (S27). Thereafter, thecontroller 226 carries out switching control on theconverter portion 225 using the voltage after the calibration such that the voltage of the target value is outputted. - It is noted that although the present exemplary embodiment is configured such that the bidirectional DC-
DC converter 30 sets the calibration value, the calibration value may be set by any of thePV converter 22, theinverter 40, and thecontroller 50. - Additionally, although, in the present embodiment, the
power generation apparatus 20, the bidirectional DC-DC converter 30, and theinverter 40 each detect the temperature in order to detect more accurate temperature, one member of theenergy management system 1 may detect the temperature, and thepower generation apparatus 20 or the like may perform a voltage correction using the detection result. -
-
- B1 SECONDARY BATTERY
- R21, R22 VOLTAGE DIVIDING RESISTANCE
- R31, R32 VOLTAGE DIVIDING RESISTANCE
- R41, R42 VOLTAGE DIVIDING RESISTANCE
- S1, S2 SWITCH
- 1 ENERGY MANAGEMENT SYSTEM
- 10 HVDC BUS
- 20 POWER GENERATION APPARATUS
- 21 OPTICAL POWER GENERATION PANEL
- 22 PV CONVERTER
- 30 DC-DC CONVERTER
- 31 VOLTAGE DETECTION PORTION
- 32 TEMPERATURE COMPENSATION PORTION
- 33 CALIBRATION VALUE SETTING PORTION
- 34 VOLTAGE CALIBRATION PORTION
- 35 CONVERTER PORTION
- 36 CONTROLLER
- 40 INVERTER
- 41 VOLTAGE DETECTION PORTION
- 42 TEMPERATURE COMPENSATION PORTION
- 43 VOLTAGE VALUE OUTPUT PORTION
- 44 VOLTAGE CALIBRATION PORTION
- 45 INVERTER PORTION
- 46 CONTROLLER
- 50 CONTROLLER
- 51 TIMING SETTING PORTION
- 101 ELECTRIC POWER SYSTEM
- 102 DISTRIBUTION BOARD
- 221 VOLTAGE DETECTION PORTION
- 222 TEMPERATURE COMPENSATION PORTION
- 223 VOLTAGE VALUE OUTPUT PORTION
- 224 VOLTAGE CALIBRATION PORTION
- 225 CONVERTER PORTION
- 226 CONTROLLER
Claims (20)
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JP2015-126178 | 2015-06-24 | ||
JP2015126178 | 2015-06-24 | ||
PCT/JP2016/067161 WO2016208400A1 (en) | 2015-06-24 | 2016-06-09 | Energy management system |
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PCT/JP2016/067161 Continuation WO2016208400A1 (en) | 2015-06-24 | 2016-06-09 | Energy management system |
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US10218214B2 US10218214B2 (en) | 2019-02-26 |
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DE102019215408A1 (en) * | 2019-10-08 | 2021-04-08 | Vitesco Technologies GmbH | Method and device for recalibrating energy meters in electric vehicles |
CN117200568A (en) * | 2023-11-06 | 2023-12-08 | 广州奥鹏能源科技有限公司 | Bidirectional inverter soft start system for energy storage power supply and control method thereof |
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US8970176B2 (en) * | 2010-11-15 | 2015-03-03 | Bloom Energy Corporation | DC micro-grid |
JP5766097B2 (en) * | 2011-11-15 | 2015-08-19 | 京セラ株式会社 | Power conditioner, control method for power conditioner, and power conditioner system |
JP2014099986A (en) * | 2012-11-14 | 2014-05-29 | Toshiba Corp | Composite power storage system |
CN103117557A (en) * | 2013-03-06 | 2013-05-22 | 东南大学 | Grid-connected current control method for combined single-phase two-stage photovoltaic generation system |
JP2015192529A (en) * | 2014-03-28 | 2015-11-02 | 株式会社三社電機製作所 | Power Conditioner |
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DE102019215408A1 (en) * | 2019-10-08 | 2021-04-08 | Vitesco Technologies GmbH | Method and device for recalibrating energy meters in electric vehicles |
CN117200568A (en) * | 2023-11-06 | 2023-12-08 | 广州奥鹏能源科技有限公司 | Bidirectional inverter soft start system for energy storage power supply and control method thereof |
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JPWO2016208400A1 (en) | 2018-03-01 |
EP3316439A1 (en) | 2018-05-02 |
WO2016208400A1 (en) | 2016-12-29 |
JP6288375B2 (en) | 2018-03-07 |
CN107743673A (en) | 2018-02-27 |
EP3316439B1 (en) | 2020-07-29 |
EP3316439A4 (en) | 2019-01-02 |
US10218214B2 (en) | 2019-02-26 |
CN107743673B (en) | 2021-01-26 |
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